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Objective To explore the effect of mucle force on contact force, peak pressure and contact area of foot joint in in vitro biomechanical experiment of foot and ankle, so as to provide references for choosing appropriate loading modes. Methods In neutral position of the ankle joint, fresh calf and foot specimens were simulated with or without mucle force loading. The contact force, peak pressure and contact area of the 1st metatarsophalangeal joint, the 2nd metatarsophalangeal joint, the 1st tarsometatarsal joint, the 2nd tarsometatarsal joint, the medial cuneonavicular joint, the intermediate cuneonavicular joint, the talonavicular joint, the calcicocuboid joint, the subtalar joint ( posterior articular surface) and the tibiotalar joint of normal foot under loading were measured, the results are compared and analyzed. Results Under muscle force loading, the contact force of the 1st metatarsophalangeal joint, the 2nd metatarsophalangeal joint, the 1st tarsometatarsal joint,the 2nd tarsometatarsal joint, the medial cuneonavicular joint, the intermediate cuneonavicular joint, the talonavicular joint and the tibiotalar joint were significantly greater than those without muscle force loading (P<0. 05), and the change percentages were 719. 28% , 311. 37% , 128. 67% , 50. 82% , 54. 89% , 57. 63% ,79. 98% and 50. 34% , respectively. The peak pressures of the 1st metatarsophalangeal joint , the 1st tarsometatarsal joint and the talonavicular joint under muscle force loading were significantly higher than those without muscle force loading ( P < 0. 05), and the change percentages were 176. 14% , 62. 91% and 40. 07% ,respectively. The contact area of the 1st metatarsophalangeal joint, the 1st tarsometatarsal joint, the intermediate cuneonavicular joint and the subtalar joint ( posterior articular surface) under muscle force loading increased significantly (P<0. 05), and the change percentages were 132. 20% , 55. 41% , 30. 97% and 26. 87% , respectively. Conclusions In biomechanical experiment of foot and ankle specimens, muscle force loading has a significant effect on contact force, peak pressure and contact area of each foot joint, especially the forefoot.Therefore, it is necessary to consider the effect of muscle force loading on stress of foot and ankle in the study ofrelated in vitro specimens
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Objective To explore the relationship between different statuses of vitamin D and parathyroid hormone (PTH) during pregnancy with glucose metabolism and the risk of gestational diabetes mellitus (GDM). Methods A total of 4138 pregnant women who had antenatal care in 3 hospitals of Hefei from March 2015 to December 2017 were recruited during 21-24 weeks. Baseline questionnaires were performed and serum 25-hydroxyvitamin D [25(OH) D] and PTH levels were measured in fasting venous blood. Glucose tolerance tests were performed during 24 to 28 weeks. Multivariate linear regression model and multivariate logistic regression model were applied to analyze the differences of glucose metabolism index and GDM risk among pregnant women at different statusesof25(OH)DandPTH.Results Theaveragelevelof25(OH)Dinthesecondtrimesterwas(39.8±16.6) nmol/L, with the median PTH 10.7 (6.9, 16.7) ng/L and the detection rate of GDM 20.4％. Covariance analysis showed no statistically significant association of vitamin D and PTH levels with glucose metabolism indexes. Pregnant women with high PTH and vitamin D deficiency had higher 1h postprandial plasma glucose ( 1hPG) , the area under the glucose curve ( AUCglu ) levels, and GDM risk compared with pregnant women with middle/lower PTH and vitamin D deficiency ( control group, all P<0.05) , and higher PTH accompanied with vitamin D non-deficiency ( Group 2, all P<0.05) . However, significant changes in glucose metabolism indicators and GDM risk were not observed in low-level PTH-pregnant women with vitamin D deficiency ( group 1) and group 2 pregnant women compared with control group. Conclusion There is an interaction between vitamin D/PTH levels and glucose metabolism during pregnancy. Vitamin D deficiency with elevated PTH level is associated with abnormal glucose metabolism.
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Objective@#To explore the relationship between the vitamin D levels and lipid metabolism during second trimester.@*Methods@#A total of 1 875 pregnant women who were in the second trimester and had antenatal care in 3 hospitals in Hefei of Anhui province from March 2015 to February 2018 were included. Baseline questionnaire survey was performed, and fasting venous blood samples were collected from the pregnant women to detect serum 25(OH)D, cholesterol (TC), triglyceride (TG), high-density lipoprotein (HDL-C) and low-density lipoprotein (LDL-C) levels. Cubic non-linear model and linear regression model were used to analyze the linear relationship between vitamin D levels and lipid metabolism indicators in the second trimester.@*Results@#The vitamin D deficiency rate was 75.3% (1 412/1 875) in the pregnant women. The mean levels of lipid metabolism indicators TC, TG, HDL-C and LDL-C were (233.22±38.87), (226.24±83.88), (79.04±12.77), and (109.54±25.95) mg/dl respectively. Multivariate linear regression model results showed, compared with Q5 of the 25(OH)D, the TC and TG levels of Q1-Q4 groups significantly increased, and the LDL-C of Q1 and Q2 groups significantly increased. The highest difference between TC, TG and LDL-C was observed in Q1 group. (TC: β=16.88, 95%CI: 10.50-23.26; TG: β=34.92, 95%CI: 21.32-48.53; LDL-C: β=9.06, 95%CI: 4.77-13.35). No significant differences in HDL-C level among the 5 groups were observed. When stratified with vitamin D deficiency the results showed that, when 25(OH)D was <50 nmol/L, TC, TG and LDL-C levels decreased by 3.53 (95%CI: 1.30-5.75), 7.42 (95%CI: 2.41 to 12.44) and 2.08 mg/dl (95%CI: 0.60-3.57) along with a 10 nmol/L increase of 25(OH)D, the difference was statistically significant, and when 25(OH)D was ≥50 nmol/L, no significant correlation was found between 25(OH)D level and TC, TG and LDL-C levels. No significant relationship between 25(OH)D level and HDL-C level was observed regardless of vitamin D deficiency.@*Conclusions@#There was a nonlinear relationship between vitamin D levels and lipid metabolism indicators in the second trimester. There was a significant negative correlation between 25(OH)D level and lipid metabolism indicators only in the deficiency of vitamin D.
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From March 2015 to February 2018, 4 728 women aged 18 to 45 years old with single-pregnancy at the gestational age of 13 to 27 weeks in Hefei were recruited to analyze the trend of vitamin D status. The average levels of serum 25(OH)D in 2015, 2016 and 2017 were (43.22±18.41) nmol/L, (39.3±15.1) nmol/L and (36.6±17.0) nmol/L, and the prevalence of vitamin D deficiency were 69.5%, 77.6% and 81.4%, respectively. Compared with 2015, the levels of serum 25(OH)D in pregnant women in 2016 and 2017 decreased by 5.23 (95%CI: 4.10-6.35) nmol/L and 7.98 (95%CI: 6.77-9.19) nmol/L. The OR (95%CI) values for the risk of vitamin D deficiency were 1.88 (95%CI: 1.57-2.24) and 2.41 (95%CI: 1.98-2.93).
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<p><b>OBJECTIVE</b>To evaluate the reliability and validity of SF-36 scale in urban residents, and provide reference for the selection of suitable health measure tools for urban residents.</p><p><b>METHODS</b>Multi-stage cluster stratified sampling was conducted to select the residents aged ≥18 years in three urbanized communities of Hangzhou. SF-36 scale was used for the measurement of the quality of life and Spearman-Brown and Cronbach' s α coefficients were used for the evaluation of split-half reliability and internal consistency reliability. The convergent and discriminative validity were evaluated by using the success rate of experiments and the criterion-related validity was evaluated with correlation analysis and non-parameter test. Structural equation modeling was used in the evaluation of contract validity.</p><p><b>RESULTS</b>SF-36 scale had good split-half reliability (R=0.94) and internal-consistency reliability (except for bodily pain and vitality, Cronbach's α range: 0.70-0.91). The convergent validity (88.57%), discriminate validity (successful rates 90.61%) and the criterion-related validity (γs=0.56, the score was consistent with the self-reported health status) were good. Second-order confirmatory factor analysis model was not well-fitted (GFI= 0.721, AGFI= 0.682, CFI= 0.731, RMR= 0.084, RMSEA= 0.098), indicating that the construct validity was poor.</p><p><b>CONCLUSION</b>The reliability, consolidation validity, discrimination validity and criterion-related validity of SF-36 scale were good, while the construct validity was poor. Improvement is needed when the scale is used for urban residents.</p>